Designing Organic Materials for Optoelectronics and Low ...
Transcript of Designing Organic Materials for Optoelectronics and Low ...
Daniel Ayuk Mbi EGBE
Linz Institute for Organic Solar Cells, Johannes Kepler University Linz,
Altenbergerstr. 69, 4040 Linz, Austria
ANSOLE e.V., Ebertstr.14, 07743 Jena, Germany
[email protected]/[email protected]
Skype: danielegbe1
Designing Organic Materials for Optoelectronics and Low Cost
Solar Cell Applications - Benefits for Africa
Inaugural Brian O´ Connell Visiting Fellows Lecture, 30 March 2016
University of the Western Cape, Cape Town, South Africa
CONTENT
• JKU Linz, Austria
• African Network for Solar Energy
• Generalities on Organic Semiconducting Materials
• Materials Design Principles• Case Study on Arylene-Ethynylene/Arylene-Vinylene Hybrid Systems
• Acknowledgements
Johannes Kepler University Linz, Austria
JKU was created in 1966, celebrates its 50th anniversary this year,
has 22 000 students studying in 4 faculties
-Faculty of Social Sciences
-Faculty of Law
-Faculty of Technical and Natural Sciences
-Faculty of Medicine (since 2014)
Linz Institute of Technology (LIT)
(since 2016)
UWC is the only African University in bilateral cooperation with JKU
Linz Institute for Organic Solar Cells (LIOS)Physics (and Chemistry) of Organic Semiconductors:
1.) Photoexcited spectroscopy
2.) Photoconductivity + Magnetoconductivity
3.) Thin film characterization
4.) Nanoscale engineering
5.) Nanoscale microscopy (AFM, STM...)
6.) In situ spectro-electrochemistry
7.) Materials synthesis
Organic/Hybrid
Solar Cells
CO2 Recycling into
Synthetic Fuels
Spectroscopy
and
Electrochemistry
(Bio)-Organic
Electronic Devices
OR
RO
OR
RO
OR
ROn
O
OMe
e-
Headed by Prof. Serdar Sariciftci
CONTENT
• JKU Linz, Austria
• African Network for Solar Energy
• Generalities on Organic Semiconducting Materials
• Materials Design Principles• Case Study on Arylene-Ethynylene/Arylene-Vinylene Hybrid Systems
• Acknowledgements
• Less than 40% of sub-Saharan Africans have access to electricity
• The present yearly economic growth of Africa is ~5.5%, despite of lack
of sufficient energy and infrastructure.
• However, Africa cannot embark on the same path as Europe, USA and
China for its development by relying only or strongly on non
environment-friendly energy sources. This is imperative in order to
achieve the Sustainable Development Goals (SDGs) (2016-2030) and
the resolution of COP 21 of maintaining the world temperature rise
not above 1.5 °C .
• The appropriate use of the abundant solar energy can be regarded as a
solution to the African energy problem. This requires highly qualified
human resources at all levels.
The Sun as Energy Source
The Sun is the primary
source of energy on Earth.
It transforms hydrogen into
helium thru nuclear fusion,
whereby energy is released
as electromagnetic rays
(photons)
The Sun as Energy Source
Every hour the Sun bathes
the Earth with enough
energy to satisfy global
energy needs for a year
Solar energy currently
accounts for about 0.1% of
the global energy demand
Solar energy is the primary
source of power for today's
space missions
Source: National Geographic/Nasa
„Within 6 hours deserts receive more energy
from the Sun than Mankind consumes within a
year“
Dr. Gerhard Knies, Desertec Initiative
Solar Panels to ring the Moon
How the moon could provide for our energyNews and Trends, January 8, 2014
11000 Km solar panels around the moon equator and transmission of energy to Earth
via microwave (Japanese project 2035)
Renewable Energies
Hydropower
Geothermal energy
Solar energy• Solarthermics• Photovoltaics
Ocean tides
Wind energy
Bioenergy (biomass)
Photovoltaics
First Generation:
Monocrystralline Si: >14%
Polycrystalline Si: >12%
Second Generation
Amorphous Si: > 6%
CdTe: > 8 %
GaAs: >18-20 %
CIGS: >10-12 %
Third Generation (New Technologies)
Grätzel-Cells: = 11 %
Organic Solar Cells: >10 %
• Perovskites: >18 %
10
Annual solar radiation -© Meteotest, Berne, Switzerland
Batteries, inverter, cables, etc
Electricity
PV panels
Solar thermalcollector Heat exchangers,
storage tank, controllers, etc
Heat Electricity
ANSOLE is a platform of exchange among various stakeholders (non-experts,
scientists, researchers, industrial experts, public and private institutions, NGO´s, etc)
who are all devoted to promote in A CONCERTED WAY the use of sustainable energy
to address the (acute) energy problem in Africa while preserving and protecting the
environment.
http://light2015blog.org/2015/06/22/the-african-network-for-solar-energy-ansole/
http://www.bbc.com/news/science-environment-34987467
www.ansole.org
Human capacity buildingis our main focus!
Participants at the Launching of ANSOLE on the 4th of February 2011
ANSOLE was initiated on the 4th of November 2010 in Sousse Tunisia and launched on the 4th of February 2011 at LIOS, JKU, Linz Austria.It celebrated its 5th anniversary this year (2016) in Cairo, Egypt.
www.ansole.org
ANSOLE members at the 5th anniversary celebration on the 4th of February 2016
Fosters technical and vocational education and training(TVET) inrenewable energies at various skill levels (capacity building)
Fosters research activities in renewable energy among Africanscientists and non African scientists who are directly involved inthe education of African students and experts (capacitybuilding)
Promotes and encourages the use of renewable energy in Africa(substainable development, environmental protection, businessmediation, etc)
Goals of ANSOLE
ANSOLE has more than 850 members based in:
42 African Countries: Algeria, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Chad,
Central African Republic, Congo-Brazzaville, Democratic Republic of Congo, Cote d´Ivoire,
Djibouti, Egypt, Ethiopia, Gambia, Ghana, Guinée Conakry, Kenya, Liberia, Lesotho, Malawi, Mali,
Mauritania, Mauritius, Morocco, Mozambique, Namibia, Niger, Nigeria, Rwanda, Senegal, Sierra
Leone, Somalia, South Africa, Sudan, South Sudan, Tanzania, Togo, Tunisia, Uganda, Zambia,
Zimbabwe.
28 non African Countries: Albania, Austria, Belgium, Britain, Canada, China, Denmark, Estonia,
Finland, France, Germany, India, Ireland, Italy, Luxembourg, Jordan, Malaysia, Holland, Palestine,
Portugal, Russian Federation, Scotland, Spain, Sweden, Switzerland,Taiwan,Turkey and USA
Logos of Institutional Members
Stand 30 March 2016
1) (Co)Organisation of RE conferences, symposia, workshops & summer schools
Cameroon 2011& 2012, Morocco 2013, Tunisia 2013, Kenya 2013, South Africa 2013, Ghana 2014,
Algeria 2015, Tanzania 2015, Egypt 2016
Upcoming: (Kenya 2016), Cameroon 2016, Burkina Faso 2016, Tanzania 2016,
Tunisia 2017, Algeria 2017,Cameroon 2017
2)Assisting in organization of non-ANSOLE RE related events worldwide
Hamburg 2011, Giessen 2012, Brussels 2012, Istanbul 2013, Berlin 2014, Dresden 2014, etc
3) Training, Education & Research
• „Sur-Place“ scholarships to selected 3rd year Bachelor, Masters and PhD students
• Mobility scholarships to Masters & PhD students (Intra-African Exchange, INEX,
Africa-North Exchange, ANEX, & Africa-Latin America Exchange, ALAMEX)
• Mediation of students & researchers from Africa, Europe, USA with own funding
to African & non-African RE laboratories
• Implementation of vocational training and education programs in RE at existing
training institutions (First initiative planned 2016 in Cameroon)
• Facilitation of building of research consortia within Africa and between Africa and
Europe
Activities
4) RE public education & awareness raising in Africa:
• radio & TV, print media, open-air events, popular theater („No Bill with the Sun“)
ANSOLE website, ANSOLE News (ANSOLE e-Magazine)
5) Business mediation
6) ANSOLE websites
information about RE events, job, training, funding opportunities, e-learning
( upcoming: ansole.com with French content!)
7) ANSOLE e-Magazine (ANSOLE News)
country specific detailed RE information; ANSOLE reports, RE events reports,
events calendar, life stories, etc (4 issues + 1 supplement published since 2014)
8) ANSOLE mailing list
• Rapid information dissemination to members, who forward the information thru
own mailing lists
9) Bridging Africa, Latin America and Europe on Water and Renewable Energies
Applications (BALEWARE)-www.baleware.org
will be launched in December 2016 in Arusha Tanzania (11-13.12.2016)
Students Exchange & Fellowship Programs
ANSOLE Sur-Place Fellowships (ANSUP)
Intra-Africa Exchange (INEX)
Africa-North Exchange (ANEX)• Africa-Latin America Exchange (ALAMEX): Upcoming
Mainly funded by the ICTP, Trieste, Italy:
And partly (~5%) by ANSOLE e.V.
Meriem Guesmi (Tunisia)Serge Izzedine (Benin/Senegal)
Alain Tossa (Benin/ Burkina Faso)
Suru Vivian John (Nigeria/South Africa)
Araba Amo Aidoo (Ghana)
Fellows 2015 & 2016
Moudarinan Aimadji (Chad/Morocco)
A. Lutgarde (South Africas Czech Rep) T. Chickri (Algeria Austria)
S. Nhi Huynh (ANEX, Sweden Namibia) M. Abdi ( ANEX, USA Cameroon)
S. Tombe (South Africa Austria)
D. Abdelrhman (Egypt France)
Some mediated students to African or European Labs
Email of Thanks
Email of Thanks
African PhD students trained at JKU through the mediation of ANSOLE since 2012
Many young African female scientists have been empowered !
Our motivation is based on the promises of God, which
are in line with The Second Law of Thermodynamics
I will bless you… and you shall be a blessing…Genesis 12:2
…I have placed before you an open door that no one can shut… Revelation 3:8
The First Law
The internal energy U of an isolated system is constant
The Second LawThe entropy S of an isolated system = universe (system+ surroundings) tends to increase
Source: Physical Chemistry for the Life Sciences, Second Edition, Peter Atkins, Julio de Paula, Oxford University Press
Level of Positive Entropy = Level of Joy and Happiness
Individual Heat = Temperature=
Level of
wealth
Entropy =
Level of joy
Amadji 3000 J 0 °C (273 K) 10.99 J/K
Daniel 3000 J 100°C (373 K) 8.04 J/K
With the same amount of energy (money/wealth/etc) more
positive entropy (= joy and happiness) is created in Amadji´s
life than in Daniel´s
Going from The First Law mindset to
The Second Law mindset
Stotal = S +Ssur
SSur = -H/T
G = -T (Stotal) = -T(S +Ssur)
G = -T(S -H/T)
G = H -TS G is the maximum non-expansion energy
G is the useful energy
Source: Physical Chemistry for the Life Sciences, Second Edition, Peter Atkins, Julio de Paula, Oxford University Press
CONTENT
• JKU Linz, Austria
• African Network for Solar Energy
• Generalities on Organic Semiconducting Materials
• Materials Design Principles• Case Study on Arylene-Ethynylene/Arylene-Vinylene Hybrid Systems
• Acknowledgements
Band Gaps in Materials
A. J. Heeger A. G. MacDiarmid H. Shirakawa
Nobel Prize 2000 in Chemistry„For the discovery and developmentof conductive polymers“
R. F. Heck E.-I. Negishi A. Suzuki
Nobel Prize 2010 in Chemistry„ for palladium-catalyzed cross couplings in organic synthesis“
A. Geim K. Novoselov
Nobel Prize 2010 in Physics"for groundbreaking experiments regarding the two-dimensional material graphene"
1977: Discovery of metallic conductivity in
iodine doped trans-polyacetylene (CH)x
**
n
1.Wessling und Gilch-Reaction (Synthesis of PPVs)
2. Horner-Wadsworth-Emmons / Knoevenagel Reactions
(synthesis of PPVs / CN-PPVs)
3. Transition Metal (Ni, Pd, Cu, Ag)-catalyzed Reactions
(Suzuki, Heck, Sonogashira, Stille, Yamamoto, etc) for the
Synthesis of PPP, LPPP, PPV, PPE, PT, PF, DA- Copolymers.
4. Metathesis –Reactions (Alkene- und Alkine-Metatheses):
PPV (Grubbs, Bazan, Thorn-Csanyi), PPE (Bunz, Moore),
PA (Feast: Durham Route)
5. Grignard-Metathesis (GRIM) Reactions for the Synthesis
of rr-P3HT and Block-Copolymers
(living chain growth polymerisation)
SSSBr
n m
P3HT: n:m = 100:0P3HT-b-P3EHT: n:m = 50:50 or 75:25 (block copolymers)P(3HT-co-3EHT): n:m = 50:50 or 75:25 (random copolymers)P3EHT: n:m = 0:100
J. Am. Chem. Soc. 2008, 130, 7812-7813.
Macromol. Rapid Commun. 2009, 30, 1059-1065.
Synthetic Methods of Conjugated Polymers
www.photonicswiki.org
Organic Semiconductors
Images source: Karl Leo, TU-Dresden
35
Organic Light-Emitting Diodes (OLEDs)
3mm thickReaction time: 0.001 mscontrast: 107:1Wide viewing angleVery low energy consumption
Source: Mitsubishi Chemicals
•Active layer: blend of conj. polymer and fullerene (OPV)
•Active layer: conj. Polymer (OLED)
•Contacts:
Electrons: Al/LiF
Holes: ITO/ PEDOT:PSS
(Poly[3,4-(ethylenedioxy) thiophene] : Poly(styrene- sulfonate))
PEDOT:PSS
Active layer
eventually LiF (6 Å)
Aluminium
ITO
Glass
Vaporisation
Spin coating,doctor blading,Printing techniques
Etching, laser-etching
Also flexiblesubstrate (PET)
38
Design of Organic Solar Cells (OSC) and Organic Light-
Emitting Diodes (OLEDS)
-3
-3.5
-4
-4.5
-5
-5.5
[eV] vs vacuum
-6
HOMO
HOMO
LUMO
LUMO
ITO PEDOT
PSS
Al
DONOR
“P"
ACCEPTOR
“N"
1.Light absorption creates bound electron-hole pair (Exciton) (EB=0.1-1eV)
2. exciton diffusion (for conj. polymers ca 5-20 nm)
3. exciton dissociation (charge separation at the interface)
4. Charge transport to the electrodes
Working Principle
39
Cathode
Anode
Substrate (PET Foil)
Cathode (ITO)
Anode (Al)
D-A-Blend
O
O
P3HTexcitation
P3HT*
PCBM(0)
P3HT+
PCBM(-I)
electron transfer
S
Working Principle of OPV
PCBM:[6,6]-phenyl-C61-butyric acid methyl ester
Efficiency = JscVocFFPin
-0.75 -0.50 -0.25 0.00 0.25 0.50 0.75-12
-8
-4
0
4
8
Curr
en
t density (
mA
/cm
2)
Voltage (V)
= 2.9 %
P3HT:PCBM
Short circuit current Jsc
(Light absorption,)
Fill factor FF(transport, charge collection)
Open circuit voltage Voc
(HOMO-LUMO offset,)
Organic Solar Cells Parameters
CONTENT
• JKU Linz, Austria
• African Network for Solar Energy
• Generalities on Organic Semiconducting Materials
• Materials Design Principles• Case Study on Arylene-Ethynylene/Arylene-Vinylene Hybrid Systems
• Acknowledgements
Low band gap (Eg < 2.0 eV)
Suitable HOMO/LUMO-energy-levels
(LUMODonor ca. 3.3-3.5 eV with PCBM as acceptor)
High absorption coefficient
Broad absorption spectrum
Sufficient charge carrier mobility(10-4-10-2 cm-2/V.s)
Optimized „ bulk heterojunction“ layer
Soluble and good film forming
Lowering the band gap
increases light absorption
but decreases VOC
LUMO
HOMO
LUMO
HOMO
Donor Acceptor
VOC
H. Hoppe et al. J. Mater. 2006, 16, 45.
S. Günes et al. Chem. Rev. 2007, 107, 1324.
G. G. Malliaras et al. Materials Today 2007,10, 34.
M. D. McGehee et al. Materials Today 2007,10, 28.
Requirements on Materials
Eg = Er + ERes + E + ESub + Eint
Er= bond length alternation BLA.
ERes = resonance energy
E= inter ring torsion angle
ESub= Substituent effects
Eint = interchain coupling
J. Roncalli Chem. Rev. 1997, 97, 173. Eg
44
Band Gap Engineering
C. L. Chochos, S. A. Choulis, Progress in Polymer Science 2011, 36, 1326-1414
Decrea
sing b
on
d len
gth
altern
atio
n (B
LA
)
O
CH3O
O
CH3O n
MEH-PPV MDMO-PPV
Eg = 2.1 eV
O
CH3O
O
CH3O
NC
CN
CN-MEH-PPV
n
n
Aromatic form ↔ Quinoid form Influence of side groups
O O
SS
nn
rr-P3HT PEDOT
Eg = 1.9 eV Eg = 1.5 eV
NH2H2N
S
O2N NO2
S
n
Eg = 1.1 eV
45
Band Gap Engineering
O
CH3O
O
CH3O
n
O
CH3O
O
CH3O n
O
CH3O
O
CH3O
O
CH3O n
Eg = 2.20 eV Eg = 2.10 eV Eg = 1.90 eV
J. Polym. Sci. Part A: Polym. Chem. 2009, 47, 2243
Chem. Rev. 2009,109, 5868.
Se
n
rr-P3HS
Eg = 1.6eV
S
n
rr-P3HT
Eg = 1.9 eV46
Coplanarity
N N
R R
N N
S
R R
NS
N
S
NS
NNSe
NN
SN
NS
N
Ph Ph
Si
R R
N
NN
S
S
N
S
S
O
OS
S
COOR
F
S
S
COR
F
S S
R R
S
Si
S
R R
S
S
OR
OR
N
RR
R
S
S
S
S
S
SS
D A
n
Electron rich ( „Donor“) building units
Electron deficient („Acceptor“) building units
Y.-J. Cheng et al. Chem. Rev. 2009, 109, 5868.47
Donor-Acceptor (Push-Pull) Concept
CONTENT
• JKU Linz, Austria
• African Network for Solar Energy
• Generalities on Organic Semiconducting Materials
• Materials Design Principles• Case Study on Arylene-Ethynylene/Arylene-Vinylene Hybrid Systems
• Acknowledgements
R
R
CH CH
I: R = H (gelb)II: R = CH3 ( gelb)
III: R = CH3O (rot)
n
H.-H. Hörhold et al. Makromol. Chem. 1970, 131,
105.
49
PPV in OLED: Burroughes, J. H. et al. Nature 1990,347,539
PPV in OPV: Sariciftci, N. S. et al. Science 1992, 258, 1474.
insoluble
n
O
On
O
On
O
On
O
On
PPV DB-PPV DO-PPV MEH-PPV MDMO-PPV
increase of solubility in common organic solvents F. Wudl et al. ACS Symp. Ser.
1991, 455, 683
J. Mater. Chem. 2011, 21, 1338-1349
R
R
n
Ar
R
R
Ar
R
R
Arn
n
poly(arylene)s poly(arylene-vinylene)s poly(arylene-ethynylene)s
PAs PAVs PAEs
R
R
R
R
Ar Ar
n
PAE-PAVs
Poly(arylene-ethynylene)-alt-poly(arylene-vinylene)s
50Prog. Polym. Sci. 2009, 34, 1023-1067
Ask, and it will be given to you; seek and you will find, knock and it will be opened to you. For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened.
Matthew 7: 7-8
Story Behind the Scene
„ You should always try to solve a problem as far as it is possible. You must be patient; that is very important“
Gerhard Erl : Nobel Prize in Chemistry 2007
N N
CH2 diurethan-spacer
n
N NCHOOHC
N N
CH2OHHOCH2
+ diisocyanate
Aldehyde + phosphonate alkene (-CH=CH-) : The birth of PPE-PPV
Story Behind the Scene
Sonogashira ReactionDrawbacks: Longer reaction time.Lower molecular weights.1 to 3% diyne defect structures.Difficulty to remove the catalyst from the end polymeric product.Advantage:Polydispersity always around 2
X =PO(OEt)2 Horner-Wadsworth-Emmons ReactionX = CN: Knoevenagel ReactionAdvantages:Shorter reaction time.
Higher molecular weight
No defect structure
Pure products after work up.
Macromol. Chem. Phys. 2001, 202, 2712-2726
OR
RO
OR1
R1O
Y
Y
n
Br
Br
OR1
R1O
Y
Y
OR
RO
OHC CHO
OR
RO+
CH2XXCH2
OR1
R1O
+
Y = HY= CN
Retrosynthetic Approach
OHC CHO
OR
RO
The rejection of the first publication led to the study of side chains effects
~40 polymers of this type have been synthesized till date
O(CH2)7CH3
CH3(CH2)7O
CH2PO(OEt)2(EtO)2POCH2
O(CH2)17CH3
CH3(CH2)17O
O(CH2)7CH3
CH3(CH2)7O
DE11= P18/8
OHC CHO
O(CH2)17CH3
CH3(CH2)17O
+
n
Story Behind the Scene
D. A. M. Egbe et al. Prog. Polym. Sci. 2009, 34, 1023 (review article)
N. Bouguerra et al. Macromolecules 2016, 49, 455-464
N. Bouguerra et al. Macromolecules 2016, 49, 455-464
Nassima Bouguerra, a Berber PhD student from Algeria
Role of side chains1. Solubilising agents
2. The donating effect contribute in lowering the band gap of polymers
3. Influence the thin film supramolecular ordering
4. Dilute the amount of photoactive species
5. Can lead to discrepancy between optical and electrochemical Eg
6. Insulating nature is good for electroluminescence
7. Can be used to tune the (nano)morphology of solar cell active layers
Macromolecules 2004, 37, 6124. Macromol. Rapid. Commun. 2005, 26, 1389.
J. Polym. Sci. Part A: Polym. Chem. 2007, 45, 1631.
Prog. Polym. Sci. 2009, 34, 1023 (review article)
Macromolecules 2010, 43, 1261.J. Mater. Chem. 2010, 20, 9726.
J. Mater. Chem. 2011, 21, 1338 (feature article)
OR1
R1O
OR2
R2On
OR1
R1O
Ooctyl
octylO
OR2
R2O
Ooctyl
octylOn
6:a =450 nm, f = 490nm, f =60-70%
8:a =470 nm, f = 520nm, f =60-80%
Increase of the
number of side
chains leads
to red shift
Photophysics in Solution
Photophysics in Thin Film
OR1
R1O
OR2
R2On
OR1
R1O
Ooctyl
octylO
OR2
R2O
Ooctyl
octylOn
Solid state properties depend on the number, position, length and
geometry of the grafted alkoxy side chains
Four-fold substitution
Eight-fold substitution
0
20
40
60
80
100
120
300 400 500 600 700 800 900 1000Wavelength / nm
Int.
(a.u
.)
DE36
DE11
Dependence of the solid state absorption and emission on the position of the side chains
DE11: a = 465 nm, Egopt = 2.39 eV, e = 602 nm, f = 19%
DE36:, a = 455, 482 nm, Egopt = 2.41 eV, e = 510, 544 nm, f = 29%
OR1
R1O
OR2
R2On
DE11=P18/8: R1 = octadecyl, R2 = octyl, orange
DE36= P8/18: R1 = octyl, R2 = octadecyl, yellow
1. P8/18: R1 = octyl, R2 = octadecyl
2. P18/8: R1 = octadecyl, R2 = octyl
3. P18/7: R1 = octadecyl, R2=heptyl
4. P18/16: R1 = octadecyl, R2 = hexadecyl
5. P18/12: R1 = octadecyl, R2=dodecyl
6. P12/12: R1 = R2 = dodecyl
1
2
3
4
5
6
a b c d e f
OR1
R1O
OR2
R2On
E. Tekin et al. J. Mater. Chem. 2006,
16, 4275-4280
Decreasing film thickness
125 100 75 65 60 50 nm
Inkjet Printed Films: Combinatorial Effects
of Side Chains and Film Thickness
Emine Tekin
Intensity increase of the PL 0-2 transition due to superposition with excimer-like emission
P8/18 P18/16 P18/8
J. Mater. Chem. 2006, 16, 4275-4280
Inkjet Printed Films: Combinatorial Effects
of Side Chains and Film Thickness
63
Tuning of solar cells active layer nanomorphology
O
O
S
O
On
O
O
S
O
On
O
O
S
O
On
VOC = 900 mV
FF= 54 %
JSC= 2.50 mA/cm2
= 1.20%
VOC = 900 mV
FF= 53 %
JSC= 3.70 mA/cm2
= 1.74%
VOC = 800 mV
FF= 44 %
JSC= 5.15 mA/cm2
= 1.80%
3: PCBM (1:3 wt)
Variation of Side Chains Volume Fraction
S
O
O
O
On
DO-PThE1-PPV2
(D1)
S
O
O
O
On
MEH-PThE1-PPV2
(D2)
2.521.510.50
2.5
2
1.5
1
0.5
0
X[µm]
Y[µ
m]
2.521.510.50
2.5
2
1.5
1
0.5
0
X[µm]
Y[µ
m]
2.521.510.50
2.5
2
1.5
1
0.5
0
X[µm]
Y[µ
m]
VOC = 840 mV
FF= 41 %
JSC= 4.5 mA/cm2
= 1.58%
VOC = 860 mV
FF= 40 %
JSC= 6.02 mA/cm2
= 2.0%
VOC = 742 mV
FF= 36 %
JSC= 4.95 mA/cm2
= 1.35%
Material (cm2.V-1.s-1)
D1 1.8 10-5
D2 2 10-6
D1:D2 2.6 10-4
Ternary Blend
G. Adam et al. J. Mater. Chem. 2011, 21, 2594
J. Mater. Chem. 2011, 21, 2594.
Getachew Adam
Phys. Status Solidi A. 2009, 12, 2695; Macromolecules 2010, 43, 1261;
Macromolecules 2010, 43, 306, J. Mater. Chem. 2010, 20, 9726
Effect of -Stacking Distance
400 500 600 700 8000,0
0,2
0,4
0,6
0,8
1,0A
bso
rptio
n O
.D.
Wavelength [nm]
AnE-PV
P3HT
Page 68
OR1
R2O
OR1
R2O
OR3
R4On
J. Mater. Chem. 14, 3462 (2004)28.03.
HL 58.7
AnE-PV
LUMO: -3.3 eV
HOMO: -5.4 eV
P3HT
LUMO: -3.0 eV
HOMO: -5.1 eV
OHC CHO
OR1
R2O
OR2
R1O6
+ (EtO)2OPCH2 CH2PO(OEt)2
OR3
R4O 14
t-BuOK
toluene
OR1
R2O
OR2
R1O
OR3
R4O
n
AnE-PV
Code R1 R2 R3 R4
AnE-PVaa octyl octyl octyl octyl
AnE-PVab octyl octyl 2-ethylhexyl 2-ethylhexyl
AnE-PVac octyl octyl methyl 2-ethylhexyl
AnE-PVad octyl octyl decyl decyl
AnE-PVae octyl octyl dodecyl dodecyl
AnE-PVba 2-ethylhexyl 2-ethylhexyl octyl octyl
AnE-PVbb 2-ethylhexyl 2-ethylhexyl 2-ethylhexyl 2-ethylhexyl
AnE-PVcc methyl 2-ethylhexyl methyl 2-ethylhexyl
d / nm
0.380 0.002
0.386 0.002
0.381 0.002
0.380 0.002
0.380 0.002
-
-
0.3790.002
Synthesis + X-Ray Data
Macromolecules 2010, 43, 306. Macromolecules 2010, 43, 1261.
O
O
O
O
O
On
O
O
O
O
O
On
AnE-PVab
AnE-PVba
Comparison between AnE-PVab and AnE-PVba
300 400 500 600 700 800 900
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
1,8
0
5
10
15
20
25
Abs
orba
nce
O.D
.
Wavelength (nm)
ab
ab:PCBM
Nor
mal
ised
PL
[a.u
.]
0
10
20
30
40
50
60
70
80
300 400 500 600 700 800 900
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
Abs
orpt
ion
O.D
.
Wavelength [nm]
ba
ba:PCBM
Nor
mal
ised
PL
[a.u
.]
O
O
O
O
O
On
O
O
O
O
O
On
Macromolecules 2010, 43, 1261.
Macromolecules 2010, 43, 306.
Comparison between AnE-PVab and AnE-PVba
d = 0.386 nm
AnE-PVab:PCBM (1:1) AnE-PVba:PCBM (1:1)
O
O
O
O
O
On
O
O
O
O
O
On
Comparison between AnE-PVab and AnE-PVba
Macromolecules 2010, 43, 1261.
-0,2 0,2 0,4 0,6 0,8 1,0 1,2
-10
-5
5
10
15
20
Cur
rent
den
sity
[mA
/cm
²]
AnE-PV ab
AnE-PV ba
Voltage [V]
3.1%
1.1%
AnE-PVab AnE-PVba
JSC : 7.14 3.44 mA
VOC: 0.79 0.93 V
FF: 55.65 34.67 %
: 3.1 1.1 %
Comparison between AnE-PVab and AnE-PVba
O
O
O
O
O
On
O
O
O
O
O
On
Macromolecules 2010, 43, 1261.
O
O
O
O
O
On
0
10
20
30
40
50
60
70
80
300 400 500 600 700 800 900
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
1,6
Abs
orpt
ion
O.D
.
Wavelength [nm]
ba
ba:PCBM
Nor
mal
ised
PL
[a.u
.]
Vivian Suru John, ANEX,
UWC, SA JKU, Austria
OHC CHO
OC8H17
H17C8O
OC8H17
H17C8O
1a: C8H17 = octyl (1)
+ (EtO)2OPCH2 CH2PO(OEt)2
OC8H17
H17C8O
t-BuOK
toluene
OC8H17
H17C8O
OC8H17
H17C8O
OC8H17
H17C8O
AnE-PVstat
n
+1b: C8H17 = 2-ethylhexyl (1)
2a: C8H17 = octyl (1)
+2b: C8H17 = 2-ethylhexyl (1)
Statistical distribution of sequences of C8H17 = octyl and of C8H17 = 2-ethylhexyl
Side Chain Based Random Copolymer
d = 0.393 nm
J. Mater. Chem. 2010, 20, 9726
µ = 5.43 ×10-4 cm2/Vs
Mn = 27,000 g/molMw = 54,000 g/mol
-0.2 0.2 0.4 0.6 0.8 1.0
-10
-8
-6
-4
-2
2
4
6
8current
density
[mA/cm2]
illumination
non
before annealing
after annealing
potential [V]
Stat:2PCBM before after
Voc [mV] 810 830
JSC [mA/cm2] 7.82 7.83
FF [%] 56 58
[%] 3.6 3.8
-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0
1E-4
1E-3
0.01
0.1
1
10
100
Photovoltaic Properties: stat
J. Mater. Chem. 2010, 20, 9726
Mn = 27,000 g/molMw = 54,000 g/mol
0.34
0.35
0.36
0.37
0.38
0.39
0.40
statccacabaead
d [n
m]
AnE-PVaa
2%
3.0% 3.8%
amorphes Polymer 1%
µ= 2.57 ×10-5 cm2/Vs
~10-5 cm2/Vs
µ = 4.52 ×10-4 cm2/Vs
µ = 5.43 ×
10-4 cm2/Vs
Possible Polymer Alignment on a Substrate (Electrode)
Edge-on alignmentFace-on alignment Vertical alignment
S. Rathgeber et al. Polymer 2011, 52, 3819-3826
• well ordered lamellar domains,
also in the presence of the fullerene,
• "face-on" domains close to the
electrodes,
• enhanced isotropic domain orientation
throughout the active layer.
This leads to the best solar cell performance!
AnE-PVstat leads to active layers with:
•Polymers with solely linear side chains align edge-on the substrate
•Polymers bearing branched side chains align face-on on the substrate
•Face-on alignment is favorable for better charge transport andconsequently for better performance
Effect of Fullerene Derivatives
P. Troshin et al. Adv. Funct. Mater. 2009, 19, 779.
0,0 0,2 0,4 0,6 0,8
-12
-10
-8
-6
-4
-2
0
2
4C
urr
en
t de
nsity, m
A/c
m2
Voltage, V
AnE-PVstat: PC61
BM
AnE-PVstat: F11
P3HT: F11
S
P3HT
OC8H17
H17C8O
OC8H17
H17C8O
OC8H17
H17C8O
AnE-PVstat
n
= 4.8-5%
Mn = 5000 g/mol
Mw= 18000 g/mol
Adv. Energy Mater. 2013, 3, 161-166
Nature Photonics 2013, 7, 811-816
Nature Photonics 2013, 7, 811-816
S. AAZOU (ANEX, Morocco-Austria)
OHC
OR
RO
S
S
S
C12H25
BrBr+Pd(PPh3)4 /CuI
iPr2NH, toluene, N2
OHC
OR
RO
SCHO
S
S
C12H25
OR
RO
OR
RO
S
S
S
C12H25
OR
RO
OR1
R1O n
OR1
R1O
CH2PO(OEt)2(EtO)2OPCH2
t-BuOK, toluene, reflux, N2
BTE-PVaa: R = R1 = octyl; BTE-PVab: R =octyl, R1 = 2-ethylhexyl; BTE-PVbb: R = R1 = 2-ethylhexyl; BTE-PVba: R =2-ethylhexyl, R1 = octyl
BTE-PV
1 2 3
4
1a, 3a, 4a: R = R1 = octyl 1b, 3b, 4b: R = R1 = 2-ethylhexyl
Two-dimensional Conjugated PAE-PAV Systems
300 400 500 600 700 8000.0
0.2
0.4
0.6
0.8
1.0
0.0
0.2
0.4
0.6
0.8
1.0 BTE-PVab
BTE-PVbb
BTE-PVba
BTE-PVaa
(b)
A
Wavelength (nm)
I em (
a.u
.)
104
105
10-5
10-4
10-3
10-2
104
105
10-5
10-4
10-3
E 1/2
(V cm-1
)1/2
h
(c
m2 V
-1 s
-1)
e (c
m2 V
-1 s
-1)
E 1/2
(V cm-1
)1/2
BTE-PVab
BTE-PVbb
BTE-PVba
BTE-PVaa
(b)
(a)
R Jadhav et al. RSC Advances,
under revision
Pune University
Journal Polym. Sci: Polym. Phys
2014, 52, 338-346
Sameh BOUDIBA, Tebessa
(ANEX, Algeria-Austria)
Shaimaa Ali MOHAMED
Zewail City of Science/
Benha University, Cairo,
(ANEX, Egypt-Austria)
CuI as versatile hole-selective contact
For organic solar cells
Solar Energy Materials & Solar Cells 2015,
143, 369-374
Colloidal PbS Quantum Dots:
Thin Film Application in Photovoltaics
Adv. Mater. 2015, 27, 1533-1539
Some Cooperation partnersDr. Harald Hoppe, University of Jena, Germany
Prof. Vera Cimrova, IMC, Prague, Czech Republic
Dr. Nadia Camaioni, CNR Bologna, Italy
Prof. Silke Rathgeber, University of Koblenz-Landau, Germany
Dr. Pavel Troshin, Russian Academic of Sciences, Moscow
Prof. Emmanuel Iwuoha, UWC, Cape Town, South Africa
Profs Samir and Amel Romdhane, University of Tunis-Elmanar, Tunisia
Dr.Kathy Schmidtke
Dr. Andreas Wild
Dr. Emine Tekin
Stefan Türk
Rupali Jadhav
Dr. Getachew Adam
Dr. Özlem Usluer
Dr. Christoph Ulbricht
Nassima Bouguerra
Sameh Boudibah
Vivian Suru John
Dr. Samuel Inack Ngi
ACKNOWLEDGEMENTS
http://jahr-der-dankbarkeit.net/
In everything give thanks; for this is the will of God in
Christ Jesus for you. 1 Thessalonians 5:18
Oct.2015 – Oct. 2016: Year of Thanfulness!
Prof. Brian O´Connell
and UWC are thanked!